This invention relates generally to graphics controllers, and more particularly to compressing frames within a graphics controller.
A graphics controller converts image data and instructions into pixels and stores the pixels in graphics or system memory until time to refresh the image on the display device, at which point the pixels are retrieved from memory and sent to the display device. When the application that is generating the image is idle, the image being displayed does not change from one refresh cycle to the next. However, the graphics controller continues to fetch the corresponding pixels in the memory for every refresh cycle. As a result, the amount of power consumed by fetching the pixels from memory is the same whether the pixels are for an idle or an active image since the power consumption is proportional to memory fetch bandwidth.